Translation factor DAP5 selective mRNA translation and m6A mRNA methylation in breast cancer metastasis

Metastasis is the leading cause of cancer-related death yet its molecular mechanisms, especially at the level of mRNA translational regulation and reprogramming still remain poorly understood. Our recent work has identified DAP5, a novel translation initiation factor, as a key player in selective mRNA translational reprogramming that is essential for metastasis. We recently showed that DAP5 along with novel cap-binding protein eIF3d, directs the selective translation of mRNAs involved in metastasis, the epithelial-to- mesenchymal transition (EMT) and cancer cell survival, but is not essential for primary tumor growth. Our unpublished data herein demonstrates that DAP5 is a novel dual m6A-specific mRNA translation initiation factor and a novel component of the m6A mRNA methyltransferase “MACOM” complex, directing 3’ untranslated region m6A modification of EMT, survival and metastasis promoting mRNAs in the nucleus which DAP5 then directs the translation of in the cytoplasm with m6A writer/reader METTL3. Our findings are highly significant and novel because we have discovered an exciting new mechanism by which selective m6A mRNA modification and translation occurs to drive breast cancer metastasis and metastatic cancer cell survival. We will test the hypothesis that in the metastatic setting, DAP5 plays a dual role, regulating both nuclear selective m6A mRNA modification as a unique metastasis mRNA-specific component of the m6A modification MACOM complex, and in the cytoplasm as a key decoder of m6A-dependent mRNA translation that is essential for EMT, and metastasis and survival of established metastases, but not for primary tumor growth. Our data suggest that in the nucleus, DAP5 replaces METTL14 in the MACOM complex, creating a "metastasis methyltransferase complex" that selectively m6A methylates mRNAs involved in metastatic progression that are then translated by DAP5 in concert with eIF3d and m6A reader METTL3 in the cytoplasm. Three Specific Aims were developed to investigate how DAP5 orchestrates selective m6A modification and translation required for metastasis, and to explore in animal models its metastasis translation functions. In Aim1 we will fully characterize the cytoplasmic and nuclear m6A methyltransferase protein complexes of DAP5 and its binding partners. In Aim 2, we will characterize the functional role of DAP5 in regulating m6A mRNA modification and translation. In Aim 3 we will characterize how blocking DAP5 interactions with the m6A methyltransferase complex or altering its nuclear/cytoplasmic localization inhibits selective m6A mRNA modification and mRNA translation and metastasis. Animal (murine) experimental models are currently still the gold standard with no realistic alternatives. For metastasis studies that test tumor cell EMT, invasion, vascular intra and extravasation, and recolonization at distant tissue sites, organoid culture development in this area is nascent and not yet representative of the natural process. Consequently, this proposal must still use (limited) animal metastatsis models. Project Number: 1R01CA314059-01 | Fiscal Year: 2026 | NIH Institute/Center: National Cancer Institute (NCI) | Principal Investigator: Robert Schneider | Institution: NEW YORK UNIVERSITY SCHOOL OF MEDICINE, NEW YORK, NY | Award Amount: $585,482 | Activity Code: R01 | Study Section: Gene Regulation in Cancer Study Section[GRIC] View on NIH RePORTER: https://reporter.nih.gov/project-details/11388121